The Upper Extremity - Clinical Tree

THE HUMERUS

The Proximal Portion of the Humerus

FIGURE 6-1, Bilateral duplicated capital humeral epiphyses in a 13-month-old child.

FIGURE 6-2, Two examples of simulated periostitis produced by the shadow of the bicipital groove in neonates, which is seen with the arm externally rotated or elevated.

FIGURE 6-3, Deep bicipital grooves that may be mistaken for an abnormality. A, A 7-month-old child. B, A 2-year-old child.

$FIGURE 6-4, A, The bicipital groove in internal rotation should not be mistaken for an impaction fracture (trough sign). B, External rotation shows no abnormality.$

FIGURE 6-5, Bicipital groove mistaken for a Hill-Sachs deformity.

$FIGURE 6-6, A, In the axillary projection, the anterior aspect of the humeral head may simulate a reverse Hill-Sachs impaction fracture. B, T2-weighted MR image shows no abnormality.$

FIGURE 6-7, On internal rotation, the humeral head may have a cystlike appearance.

FIGURE 6-8, Beaking of the epiphyseal line in a 16-year-old boy. This beaking, particularly of the epiphysis, is seen elsewhere and should not be mistaken for an avulsion injury.

$FIGURE 6-9, The normal epiphyseal lines of the proximal humerus in a 17-year-old boy. A, External rotation. B, Internal rotation. The epiphyseal line in B at times is mistaken for a fracture.$

$FIGURE 6-10, The lateral aspect of the epiphyseal line is normally quite wide and should not be mistaken for evidence of a fracture.$

FIGURE 6-11, The closed epiphyseal line in an 18-year-old man simulates a lesion on CT scan.

FIGURE 6-12, Bilateral upper humeral notches in an 11-year-old boy. Seen in children between 10 and 16 years of age, such notches represent a phase of growth. They are probably similar to the cortical lesions seen in the distal humerus, the distal end of the radius, the distal end of the femur, and the proximal end of the tibia.

FIGURE 6-13, Other examples of upper humeral notches. A, A 1 , A 12-year-old boy. B, B 1 , A 12-year-old girl. Note how these variants may resemble the changes of malignancy.

FIGURE 6-14, Very deep upper humeral notch in a 7-year-old boy.

FIGURE 6-15, Residual upper humeral notches in adults. A, A 28-year-old woman. B, A 29-year-old woman. C, A 35-year-old woman.

FIGURE 6-16, A, B. The upper humeral notch shown as a radiolucency in internal rotation.

$FIGURE 6-17, A, Simulated fracture of the greater tuberosity produced by positioning in external rotation. B, No fracture seen with internal rotation.$

FIGURE 6-18, Two examples of how projection of the cortex of the humeral neck can simulate periostitis.

FIGURE 6-19, Examples of simulated destruction of the greater tuberosity. This appearance is the product of the lesser amount of cancellous bone present in this location. It is nicely demonstrated by MR images in Figure 6.20 .

FIGURE 6-20, T1-weighted and gradient echo T2-weighted MR images of the shoulder show the areas of cancellous bone in the greater tuberosity that give the appearance shown in Figure 6.19 .

FIGURE 6-21, A striking example of the pseudocyst of the greater tuberosity.

FIGURE 6-22, Epiphyseal and metaphyseal spurs in a 15-year-old boy.

FIGURE 6-23, The lesser tuberosity seen in external rotation ( A and B ) and in internal rotation ( C and D ).

FIGURE 6-24, Metaphyseal spurs in a 19-month-old child. These are normal variants of growth.

FIGURE 6-25, Cortical thickening underlying the deltoid muscle in a 2-month-old child.

FIGURE 6-26, Tendinous insertions in a 20-month-old child that may simulate periostitis.

FIGURE 6-27, A, B, The humeral pseudocyst in a 12-year-old boy.

FIGURE 6-28, A, B, Prominent deltoid muscle insertion in two projections in a 50-year-old man (←). The medial shadow in A is a soft tissue fold ( ).

FIGURE 6-29, Unusually prominent deltoid muscle insertions seen bilaterally.

FIGURE 6-30, Localized cortical thickenings caused by a prominent deltoid muscle insertion.

FIGURE 6-31, Large deltoid muscle insertion confirmed on axial MR image. A, Plain film. B, T1-weighted axial MR image.

FIGURE 6-32, The deltoid insertion on a T1-weighted MR image.

FIGURE 6-33, Radiolucencies produced by the insertion of the pectoralis major muscle. A, Plain film. B, Tomogram.

FIGURE 6-34, The same entity as shown in Figure 6.33 , seen here bilaterally in a heavily muscled 19-year-old man.

FIGURE 6-35, A discrete pectoralis major muscle insertion.

FIGURE 6-36, A , B, Insertion of the coracobrachialis muscle.

FIGURE 6-37, Cortical thickenings of the medial and posterior cortex at the insertion of the latissimus dorsi muscle in a 55-year-old man.

FIGURE 6-38, Latissimus dorsi muscle insertions in a 68-year-old man with foci of endosteal thickening.

FIGURE 6-39, Spurlike insertion of the latissimus dorsi muscle.

FIGURE 6-40, A, Benign cortical defects of the humerus in a 4-year-old child ( ). Note also the location and appearance of the ossification centers for the greater tuberosity and head of the humerus at this age ( ). B, Five years later, the cortical defect in the left humerus has disappeared, and that in the right has left a sclerotic scar.

FIGURE 6-41, Multiple benign cortical defects of the proximal humerus. These fibrous lesions may be single or multiple and are of no clinical significance.

FIGURE 6-42, Two examples of “herringbone” trabecular pattern of the medullary cavity of the humerus.

$FIGURE 6-43, A and B, Left humerus of a 26-year-old woman with a “herringbone” medullary pattern. C, The same patient's right humerus 2 weeks after casting for a fracture of the surgical neck. Note the peculiar type of deossification, which occurs in patients with this type of medullary trabecular pattern and resembles metastatic neoplasm or multiple myeloma.$

FIGURE 6-44, A, B, Another example of “aggressive” osteoporosis, this one in a 50-year-old woman recently immobilized secondary to brain tumor. C, T1-weighted MR image shows normal fatty bone marrow.

FIGURE 6-45, A, B, Intramedullary sclerosis of humerus in a 68-year-old woman similar to that seen in the femur of the elderly (see Fig. 7.70 ).

FIGURE 6-46, Two examples of physiologic “periostitis” of the newborn. A, A 3-month-old infant. B, An 8-month-old infant. This finding is not seen before age 1 month and is usually symmetric in distribution, although not necessarily concentric, and may be seen in only one view.

The Distal Portion of the Humerus

FIGURE 6-47, Normal thin flange of bone above the lateral epicondyle simulating periostitis (←). Note also the perforated olecranon fossa ( ).

FIGURE 6-48, Another example of “periostitis” simulated by the lateral epicondylar flange.

$FIGURE 6-49, The epicondylar flange simulating a cortical fracture.$

FIGURE 6-50, Olecranon foramen with marked sclerosis of its margins.

FIGURE 6-51, The supracondylar process. This vestigial structure is rarely associated with symptoms and occurs in about 1% of persons of European origin. Its axis is typically directed distally.

FIGURE 6-52, The supracondylar process in a 4-year-old boy.

FIGURE 6-53, A supracondylar process-directed cephalad rather than in the usual caudad direction.

FIGURE 6-54, Developmental cortical notch on the medial cortex of the humerus is of no significance. Its anatomic origin is uncertain.

FIGURE 6-55, Another example of the humeral cortical notch.

FIGURE 6-56, A, B, Two examples of small fossae on the anterior cortex of the distal humerus, which are probably developmental.

FIGURE 6-57, Variations in appearance of the olecranon fossa. A, Fossa is replaced by a complete foramen (←). B, Foramen is traversed by a bridge of bone ( ).

$FIGURE 6-58, Simulated loose body or fracture produced by the ossification center for the olecranon process in a 7-year-old girl.$

FIGURE 6-59, The normal rarefaction of bone of the distal humerus may simulate a lytic lesion on the lateral projection.

FIGURE 6-60, Apparent discontinuity of bone immediately above the epiphyseal line in a 12-year-old boy. This finding represents a variation in development of the metaphysis of a long bone in adolescence similar to the cortical lesions seen in the proximal end of the humerus, the distal radius, the distal end of the femur, and the proximal end of the tibia. This appearance may be misconstrued as evidence of dislocation of the epiphysis or a destructive lesion of the humerus.

FIGURE 6-61, The discontinuity seen in Figure 6.60 is now only minimally present in this 16-year-old boy, indicating the transient nature of this finding.

FIGURE 6-62, Early appearance of the ossification center for the trochlea in a 6-year-old girl. Rarely the trochlear ossification center may appear without evidence of a medial epicondylar center, as in this case.

FIGURE 6-63, Normal position of the ossification center for the lateral epicondyle in a child, simulating an avulsion.

FIGURE 6-64, Normal appearance and position of the ossification center for the medial epicondyle in a 7-year-old boy.

FIGURE 6-65, A, Simulated dislocation of the ossification center for the medial epicondyle caused by suboptimal patient positioning. B, Frontal projection. Note the absence of a medial hematoma, which would accompany a dislocation of the ossification center.

FIGURE 6-66, The medial epicondyle in the adult seen in off-lateral projection.

$FIGURE 6-67, Normal irregularities and pseudofractures of the ossification centers of the distal humerus in a 10-year-old girl. Note the lack of bilateral symmetry of some of these defects.$

FIGURE 6-68, A persistent epiphysis of the capitellum in an adult. Left and center, Radiographs. Right, Tomogram.

$FIGURE 6-69, Bilateral cleft epiphyses for the medial epicondyle in a 15-year-old boy. The left elbow was immobilized for 2 weeks on the assumption that the cleft represented a fracture.$

FIGURE 6-70, Marked asymmetry of ossification of the centers for the trochlea in an adolescent girl.

$FIGURE 6-71, An example of how the epiphysis of the trochlea may be mistaken for a fracture in the lateral projection.$

FIGURE 6-72, Asymmetric development of the epiphysis for the capitellum in a 12-year-old boy. Such normal asymmetries in architecture and rate of growth are particularly common in the elbow and should not be misconstrued as evidence of trauma.

$FIGURE 6-73, A, Simulated fracture of the ossification center of the medial epicondyle in a 14-year-old boy, produced by the superimposed radiolucent shadow of the growth plate between the ossification center and the bony side wall of the humerus (←). Note also the unusual appearance of the trochlea resulting from filming in a slight degree of flexion ( ). B, Note the radiolucency of the growth plate of the trochlea in lateral projection.$

$FIGURE 6-74, Normal irregularities in ossification of the capitellum, which should not be mistaken for a fracture.$

$FIGURE 6-75, Several simulated fractures of the ossification centers of the distal humerus in an 11-year-old boy. Such irregularities of ossification are common.$

FIGURE 6-76, A and B, Normal asymmetry in development of ossification centers. In B, note the absence of the ossification center for the lateral epicondyle in an 11-year-old girl.

FIGURE 6-77, Incomplete union of ossification centers for the epicondyles in a 44-year-old woman.

FIGURE 6-78, Incomplete union of the ossification centers for the epicondyles in a 54-year-old woman.

FIGURE 6-79, Examples of failure of union of ossification centers in adults.

FIGURE 6-80, Projection of the middle eminence of the lower articular surface of the humerus.

FIGURE 6-81, Small bilateral ossicles related to the articular surface of the humerus. These may represent separate ossification centers for the middle eminence. Arthrograms indicate that they are enclosed in a lucent cartilage envelope.

FIGURE 6-82, An additional example of the entity shown in Figure 6.81 .

FIGURE 6-83, A, B, Two examples of paratrochlear bones at the lateral humeral condyle.

FIGURE 6-84, Spurlike shadows probably representing the edge of the capitellum in an 11-year-old boy.

$FIGURE 6-85, A, Simulated fracture through the epiphysis of the trochlea produced by angulation of the beam. B, Comparison view of the opposite elbow in true lateral projection shows a similar lucency without the simulated fracture.$

FIGURE 6-86, Circumscribed radiolucencies in metaphyses caused by fossae above the capitellum.

FIGURE 6-87, The normal lucency just above the joint in lateral projection, which should not be mistaken for an elevated fat pad.

FIGURE 6-88, The posterior fat pad may be seen in some normal individuals with the elbow in extension. Left, Partial flexion. Right, Extension.

THE FOREARM

The Proximal Portion of the Forearm

FIGURE 6-89, A, B, Normal asymmetry of development of the olecranon apophyses. Note irregular ossification in B.

FIGURE 6-90, Patella cubiti, a sesamoid bone in the triceps tendon.

FIGURE 6-91, Patella cubiti in a more inferior position.

$FIGURE 6-92, A separate nucleus of ossification for the olecranon process, not a fracture.$

FIGURE 6-93, Other examples of separate apical nuclei of ossification for the olecranon process.

$FIGURE 6-94, A, Normal appearance of the uniting olecranon ossification center in an adolescent. B, Incomplete union of the ossification center of the olecranon process—not a fracture—in an adult.$

FIGURE 6-95, Persistent unfused apophyses olecranon in a middle-aged man.

$FIGURE 6-96, Simulated fracture of the ulna produced by trabeculations in the shaft (←) and a small excrescence in the cortex just below the location of the distal end of the unossified apophysis ( ).$

FIGURE 6-97, Unusual development of the olecranon. A, Ossicle. B, Fossa.

FIGURE 6-98, Residual irregularity of the olecranon after closure of the apophysis in a 19-year-old man.

FIGURE 6-99, Normal foramina for nutrient vessels of the proximal ulna.

FIGURE 6-100, Cancellous bone of the proximal ends of the ulnae, simulating destructive lesions in a 49-year-old man.

FIGURE 6-101, Normal sclerotic appearance of the epiphyses of the radial heads in an 11-year-old boy.

FIGURE 6-102, Cleft epiphysis of the radial head.

FIGURE 6-103, Notches on the lateral aspects of the radial metaphyses in a 6-year-old girl. Such notches are filled in by further growth and disappear as the child matures (see Fig. 6.104 ).

FIGURE 6-104, This film illustrates the mechanism by which the notches seen in Figure 6.103 are obliterated. The fossa fills in by overgrowth of the epiphysis of the radial head. This is the same mechanism seen for completion of growth of the tibial tubercle.

$FIGURE 6-105, Small cleft that might be mistaken for fracture in the medial aspect of the proximal radial metaphysis. There was no history of trauma.$

FIGURE 6-106, A small spur arising from the radial head.

FIGURE 6-107, Accessory ossicle at the tip of the coronoid process. Old avulsion injuries may also manifest as ossicles of this type.

$FIGURE 6-108, Accessory ossification centers for the tip of the coronoid process that could be mistaken for a fracture.$

$FIGURE 6-109, Persistent ossification center of the coronoid process of the ulna simulating a fracture.$

FIGURE 6-110, Examples of fossae in the ulna that represent the insertion point of the annular ligament. They should not be confused with a pathologic process.

FIGURE 6-111, Unusually long coronoid process of the ulna, possibly related to stress.

$FIGURE 6-112, Oblique radiolucent clefts in proximal radial metaphyses in a young child. These oblique clefts are common findings adjacent to the epiphyseal lines in young children and should not be mistaken for metaphyseal fractures.$

FIGURE 6-113, The radial tuberosity manifests as a radiolucency and might be mistaken in both projections for an area of bone destruction.

FIGURE 6-114, A radial tuberosity in a 4-year-old boy simulating a focal destructive lesion only in the lateral projection.

FIGURE 6-115, The interosseous ridges of the radius and ulna often cast shadows that may be mistaken for periostitis.

FIGURE 6-116, Physiologic “periostitis” of the newborn in a 2½-month-old infant. This is not seen before age 1 month, is symmetric in distribution although not necessarily concentric, and may be seen in only one view.

FIGURE 6-117, The nutrient channel of the radius.

FIGURE 6-118, Normal undulations in contour of the radii of the newborn. These disappear with age.

FIGURE 6-119, Cortical tunneling of the distal ulna may be seen in infants and older children and is of no clinical significance.

FIGURE 6-120, A, B, Bilateral physiologic bowing of both bones of the forearm seen in a patient with ulna minus variation.

The Distal Portion of the Forearm

FIGURE 6-121, Small normal metaphyseal spurs of the distal radius in a healthy 1-year-old girl.

FIGURE 6-122, Dense zones of provisional calcification not shown elsewhere. This is a normal phenomenon about the age of 2 years.

FIGURE 6-123, Normal metaphyseal irregularities of the radius in a 14-year-old boy. These changes were no longer present 1 year later.

FIGURE 6-124, Two examples of thin flanges of bone simulating periostitis of the distal radius.

FIGURE 6-125, Examples of cortical irregularities at insertion of interosseous membrane simulating periostitis.

FIGURE 6-126, Developmental fossa in distal ulna.

FIGURE 6-127, Ulna plus variation with wide separation of the distal ulna and radius.

FIGURE 6-128, Unusually long ulna (ulna plus variant), which may be mistaken for a dislocation of the distal radioulnar joint if the bilateral symmetry is not noted.

FIGURE 6-129, Apparent dorsal dislocation of the ulna caused by curvature of the shaft, which can be seen in the lateral projection.

FIGURE 6-130, Normal spurlike projections of the epiphysis at the epiphyseal line simulating avulsion injuries.

FIGURE 6-131, Two examples of epiphyseal spurs on medial and lateral aspects of the distal radius.

FIGURE 6-132, Residual epiphyseal spur after closure of the epiphyseal plate in a 20-year-old man.

$FIGURE 6-133, Closed epiphyseal spur at the edge of the closed physis mistaken for an avulsion fracture.$

FIGURE 6-134, Large residual epiphyseal spur that might be mistaken for an avulsion.

FIGURE 6-135, Remnants of the epiphyseal line in a 20-year-old man.

FIGURE 6-136, Small spicules in the epiphyseal cartilage of the ulna in a healthy 11-year-old girl. This is a normal finding of no significance.

FIGURE 6-137, Spicule in the epiphyseal cartilage of the radius of a 12-year-old boy.

FIGURE 6-138, Spicules in the epiphyseal cartilage of the ulna with long streaks in the shaft in a healthy 12-year-old boy.

FIGURE 6-139, Normal extension of the epiphysis into the physis similar to Krump's hump in the ankle.

FIGURE 6-140, Normal extension of the metaphysis into the physis of the ulna.

$FIGURE 6-141, Discordant closure of the physis of the radius and ulna is normal and therefore not useful in diagnosing Salter I fracture.$

FIGURE 6-142, Deep symmetric fossae below the radioulnar joint simulating erosions.

$FIGURE 6-143, Simulated fracture of the radial epiphysis produced by superimposed projection of the epiphyseal plate at different levels.$

FIGURE 6-144, Examples of cleft distal ulnar epiphyses.

FIGURE 6-145, Unilateral cleft ulnar styloid epiphysis in a 14-year-old boy.

FIGURE 6-146, Cleft distal radial epiphysis seen only in the oblique projection. Any epiphysis or apophysis may develop from multiple centers.

$FIGURE 6-147, Separate ossification centers for the radial styloid process, which may persist into adult life and be mistaken for fracture.$

$FIGURE 6-148, Accessory ossicle of the end of the ulnar styloid, which should not be mistaken for a fracture.$

FIGURE 6-149, Unusual lucencies of the medial aspects of the ulnar epiphyses.

FIGURE 6-150, Two examples of ununited ossification centers of the ulnar styloid process. A, A 15-year-old patient. B, A 27-year-old patient.

FIGURE 6-151, Accessory ossicles at the ulnar styloid that articulate with the styloid process.

FIGURE 6-152, Unusual length and configuration of the ulnar styloid processes.

$FIGURE 6-153, Not all styloid ossicles are developmental; some may be traumatic in origin. Left, Fracture of the ulnar styloid in a 16-year-old patient. Right, At age 26 years, the fracture fragment has evolved into an ossicle.$